[71.20] Three-Dimensional Numerical Simulations of Type Ia Supernovae: The Third Second

We continue to study thermonuclear explosions of
carbon-oxygen white dwarfs (WD) using a three-dimensional
reactive fluid dynamic model. Our previous numerical results
obtained for the first 1.8-2.0 s of the explosion show that
the explosion is likely to involve a thermonuclear
detonation that appears after the initial deflagration
stage. Here we model the propagation of the detonation wave
and the evolution of the expanding WD for later times. The
results show that by 3 seconds after the beginning of the
explosion, the WD radius increases by a factor of 20, the
temperature in the center of the WD drops below 109 K,
and the material continues to expand without energy release.
Outer layers of WD still contain unburned carbon in some
locations and are accelerated to velocities above 20,000
km/s.

This work was supported in part by the NASA ATP program
(NRA-02-OSS-01-ATP) and by the Naval Research Laboratory
(NRL) through the Office of Naval Research. Computing
facilities were provided by the DOD HPCMP program.